Purpose

This article guides you through the installation and configuration of OpenSSL. You may want to install and configure OpenSSL to be able to create custom certificates for vSphere environments. It also helps to eliminate common causes for problems and ensure that the requests generated are appropriate for vSphere environments.

Resolution

Overview

OpenSSL can be used for creating certificate requests and also as a certificate authority. Although the steps that are used to generate the certificate are different, the setup and configuration steps are the same as the certificates that vSphere uses are X.509 v3 SSL certificates. Only the way in which the actual certificate is generated is different.

Setup

Important: Ensure that you are using OpenSSL version 0.9.8. If you do not use this version, the SSL implementation will fail.To setup OpenSSL:

Ensure that the Microsoft Visual C++ 2008 Redistributable Package (x86) is installed on the system on which you want to generate the requests. To download the package, see the Microsoft Download Center.

Launch the installer and proceed through the installation and note the appropriate directory for later use. By default, it is located at c:\OpenSSL-Win32.After this program is installed, you must configure it to issue vSphere certificates.Note: The preceding links were correct as of July 29, 2013. If you find a link is broken, provide feedback and a VMware employee will update the link.

Configuration

To configure OpenSSL follow these steps:

Take a backup of the openssl.cfg file. By default, this file is located at the c:\OpenSSL-Win32\bin directory.

Save and close the file.The installation is now set to configure a certificate for the server that you have entered in the file. You can repeat this configuration by creating separate files for each server request or by not specifying a value. If you do not specify a value, OpenSSL prompts you for the information.Note: The preceding modified file will not prompt you for information because all information is configured within the file.

The advisory documents CVE-2013-5973 “VMware ESXi and ESX unauthorized file access through vCenter Server and ESX”. This issue may allow certain unprivileged users on vCenter Server access to arbitrary files on ESXi/ESX and may allow local unprivileged users on ESX (i.e. ESX 4.0 and ESX 4.1) access to arbitrary files. Modification of files on ESXi or ESX may allow for code execution after a host reboot.

VMware ESXi and ESX contain a vulnerability in the handling of certain Virtual Machine file descriptors. This issue may allow an unprivileged vCenter Server user with the privilege “Add Existing Disk” to obtain read and write access to arbitrary files on ESXi or ESX. On ESX, an unprivileged local user may obtain read and write access to arbitrary files. Modifying certain files may allow for code execution after a host reboot.

Unpriviledged vCenter Server users or groups that are assigned the predefined role “Virtual Machine Power User” or “Resource Pool Administrator” have the privilege “Add Existing Disk”.

In a default vCenter Server installation no unprivileged users or groups are assigned the predefined role “Virtual Machine Power User” or “Resource Pool Administrator”.

Restrict the number of vCenter Server users that have the privilege “Add Existing Disk”.

VMware would like to thank Shanon Olsson for reporting this issue to us through JPCERT.

The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2013-5973 to this issue.

Column 4 of the following table lists the action required to remediate the vulnerability in each release, if a solution is available.

Known Issues (*)

Deploying these patches does not remediate the issue if the ESXi or ESX file /etc/vmware/configrules has been modified manually (modifying this file is uncommon). Customers who have modified this file should apply the workaround after installing the patch.

After deploying the patches, Virtual Machines that have their names ending in “-flat”, “-rdm” or “-rdmp” will no longer power on. See the VMware Knowledge Base article listed under “Workaround” for a solution.

4. Solution

Please review the patch/release notes for your product and version and verify the checksum of your downloaded file.
ESXi and ESX
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Security Hardening Guides provide prescriptive guidance for customers on how to deploy and operate VMware products in a secure manner. Guides for vSphere are provided in an easy to consume spreadsheet format, with rich metadata to allow for guideline classification and risk assessment. They also include script examples for enabling security automation. Comparison documents are provided that list changes in guidance in successive versions of the guide.

VMware
The VMware® vCloud™ Director Security Hardening Guide helps users who are embarking into the journey of cloud computing understand key security elements and technologies found in VMware’s vCloud Director product. It also provides guidelines and best practices for installation, configuration and operation of secure clouds based on VMware’s vCloud Director.